2020 年 88 巻 3 号 p. 190-194
In the plasma/liquid (P/L) interfacial reaction, nitrogen fixation is performed on a water phase surface. In the P/L reaction, discharged nitrogen gas reacts with water molecules at the interface between the plasma gas phase and the water phase, followed by either a reduction reaction, ammonia production or oxidation reaction, nitric acid production. The production of nitric acid in the P/L reaction is influenced by the concentration of oxygen present in each gas phase and water phase, and the atomic nitrogen contained in the nitrogen plasma. For the reduction reaction at the P/L reaction locus, the water phase was modulated in order to make ammonia production dominant in nitrogen fixation. Ammonia is released into the gas phase under conditions of high water temperature and high pH. To obtain only ammonia using this reaction, it is necessary to incorporate a process for raising the temperature of the water. In the P/L reaction, only the ammonia gas can be obtained in one-step by using the rise in water temperature due to the discharged heat plasma gas. A reaction system was developed to control the water and the gas phase to enable high purity ammonia trapping as released by the gas phase.